A system which detects, for example, through multiple sensor units, temperatures and degree of humidity at multiple locations of a cultivation facility for vegetables and flowers, and further an entering to or leaving from that facility, and which notifies a managing person of the occurrence of an abnormal event is disclosed (see, for example, Patent Literature 1). According to this system, each of the multiple sensor units is set with a priority. The higher the priority of the sensor unit is, the shorter the cycle of obtaining the sensor value through polling is set, and the lower the priority of the sensor unit is, the longer the cycle of obtaining the sensor value through polling is set.
In addition, a system that monitors and controls, through a master-station device, the operating statuses of multiple slave-station devices, and the operation statuses of the facility is disclosed (see, for example, Patent Literature 2). According to this system, the master-station device is provided with a parameter block that registers the specifity, importance, priority, and relevancy of the position information of the slave-station device. The master-station device changes the order of polling or the cycle thereof, changes the order of searching and the cycle thereof, and forms a closed loop among the slave-station devices based on the specifity, importance, priority, and relevancy of the position information of the slave-station device registered in the parameter block. Hence, an optimized control of the multiple slave-station devices is enabled with a high efficiency.